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Composting at Vancouver Landfill

In 1989, the City of Vancouver began a leaf composting program at the Vancouver Landfill. In 1995, this facility was expanded to a 1.8-hectare paved composting facility to accommodate all types of yard and garden trimmings.

Over 37,000 tonnes of trimmings are composted each year. Composting diverts trimmings from the Landfill, conserving landfill space while helping to achieve the solid waste reduction goals set out in the regional Solid Waste Management Plan.

The Composting Process

Composting Facility Click to Enlarge Image

Yard and garden trimmings include grass, leaves and plant debris and are dropped off in the receiving area. A garbage bin is available in the receiving area for any unacceptable materials that arrive with the trimmings.

An excavator loads the material into an infeed hopper. A drag chain moves the trimmings onto a vibrating finger screen and over a metal detector.

Plastic, metal and other foreign matter are removed by hand before the trimmings enter the grinder. Small bits of plastic are very difficult to separate from the final product.

The trimmings then enter the grinder, which consists of a 400-HP hammer hog. The grinder produces material with maximum length of 7cm. This material exits the grinder by a conveyor. 

Ground material is placed into long piles, called windrows, with a front end loader. A windrow turner is used to turn the windrows periodically to maintain optimum temperature, oxygen levels and moisture content.

After approximately three months, the windrowed material is moved to a curing pile for about nine months to stabilize the compost. A reduction of about 30% by volume is achieved through the composting process.

A trommel screen is used to screen the cured compost to 1.25 or 2 cm in size.

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Environmental Protection

Run-off from the composting process, also called leachate, is captured by the Landfill's leachate collection system.

Compost is sampled according to requirements set out by the Ministry of Water, Land and Air Protection. Compost quality is determined by an independent laboratory and has met all provincial standards to date.

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Local Composting Projects

Over 33,000 cubic metres of compost are produced each year and used mainly as landscaping mulch or blended with other products to produce topsoil. Compost is sold to residential gardeners, commercial landscapers and municipal parks boards. In 1999, compost was utilized to restore Hastings Park in East Vancouver and to reconstruct two large athletic fields.

Hastings Park Click to enlarge image

Restoration of newly constructed areas in Hastings Park was accomplished using compost pre-blended with sand at a 3:1 ratio (compost:sand). This material was spread at a depth of 30 cm over three hectares.

Compost was used in the reconstruction of athletic fields at Hillcrest Park and New Brighton Park in Vancouver to improve drainage on the fields.  Sand was first spread on the sites, followed by a 7 cm uniform layer of compost spread with manure spreaders. The compost was mixed into the sand with rotary tillers.

In all three projects, compost dramatically improved the growth rate of grass and other plants.

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